Method, arrangement, device and magazine for automatic changing of knife units of a knife ring of a knife ring slicing device

ABSTRACT

In a method and device for automatically exchanging knife units of a knife ring slicing device, the knife changing magazine is moved relative to the knife ring into a knife changing position in which the knife receptacles of the knife changing magazine are axially aligned with the knife receptacles of the knife ring. The worn knives of the knife ring are moved axially into empty knife receptacles of the knife changing magazine. A relative movement between the knife changing magazine and the knife ring is carried out until the knife changing magazine and the knife ring are again in a knife changing position in which the knife receptacles with resharpened knife units are aligned with the knife receptacles in the knife ring. The resharpened knife units are introduced in the opposite axial direction into the knife receptacles of the knife ring from which the worn knife units had been removed.

This application is a divisional of U.S. patent application Ser. No.10/151,718, filed May 18, 2002.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a method, an arrangement, and a device forautomatically changing knife units of a knife ring of a knife ringslicing device, wherein a knife changing magazine provided withresharpened knife units is moved into a defined knife changing positionrelative to the knife ring in which at least some of the knifereceptacles in the knife changing magazine are axially aligned with atleast some of the knife receptacles in the knife ring. In particular,the invention relates also to a device for comminuting materialespecially in the form of a knife ring slicing device, comprising a toolring, which has uniformly distributed about its circumference toolreceptacle for the comminution tools, and comprising a unit for pushingout the comminution tools, arranged on the periphery of the device,wherein the unit for pushing the comminution tools comprises severalpushing elements which are axially aligned with the comminution tools tobe pushed out and are advanced and retracted axially into and out of thetool receiving units of the tool ring by means of an advancing drive.The invention furthermore relates to a knife changing magazine forautomatically changing the knife units of a knife ring, wherein theknife changing magazine has areas with receptacles for the knife unitsof a knife group to be exchanged at once.

2. Description of the Related Art

For producing wood strands as the starting material for manufacturingboard-shaped structural components, slicing machines are known whosecomminution tools are arranged in a stationary or rotating knife ringand operate relative to a stationary or rotating abutment. The strandsproduced in this way pass in the radial direction through the knifering. The quality of the final product is greatly affected by thequality of the strands used as the starting material. The strands shouldhave cut surfaces as smooth as possible and also identical dimensions.In order to ensure a constantly high quality of the strands, it must beensured that the comminution tools always have sharp cutting edges inorder to achieve comminution by means of cutting and, to a lesserdegree, by squeezing or breaking or grinding. Sharp comminution toolshave also the advantageous side effect of a reduced electric energyconsumption of the comminution machine.

During operation of a comminution machine, the comminution tools aresubjected to natural wear. The degree of wear depends on variousfactors, for example, the type of wood and moisture contents of the woodof the starting materials as well as the advancing speed andcircumferential speed of the cutting tools as well as on constructiveparameters such as the cutting angle and the material properties of thecomminution tools. The strongest wear effect can be observed on thecutting edges of the comminution tools which become more and more bluntwith increasing service life so that during the generation of woodstrands a smooth cut can no longer be ensured. This causes at the sametime a decrease of the strand quality, an increase of the undesirableproportion of fine particles in the wood strands and, as a result ofthis, an increase of the required amount of bonding agent as well as anincrease of energy consumption of the slicing machine.

In order to avoid these disadvantages, it is required to perform a knifeexchange in regular intervals wherein the worn or spent comminutiontools are replaced by resharpened ones. Under regular conditions such aknife exchange is carried out in time intervals of three to eight hours.Since all comminution tools of a knife ring must be exchanged in such aknife exchange operation, this requires a considerable temporalexpenditure which causes long downtimes of a comminution machine. Inconnection with known methods and devices for exchanging the comminutiontools, which are performed manually or semi-automatically, a knifeexchange takes approximately 20 to 40 minutes. For an average servicelife of the comminution tools of four hours, this causes a productionloss of three hours per day. Accordingly, the resulting product lossrelative to a nominal strand production output makes it necessary todesign the comminution device for higher comminution output in order toensure the continuous further processing of the produced strands in thesubsequent processing steps. This entails providing larger bunkercapacities as a buffer for bridging the production loss caused by theknife exchange.

In order to circumvent these disadvantages, attempts have been made toshorten the duration for a knife exchange. From German patentapplication 199 21 383 A1 and U.S. Pat. No. 5,313,696, a method and adevice for changing the comminution tools of comminution devices areknown in which the complete knife ring of the comminution device isremoved and replaced by a second knife ring furnished with resharpenedcomminution pools.

For removing the worn or spent knife ring according to German patentapplication 199 21 383 A1, a tool exchange carriage is used which ismoved in front of the end face of the comminution device and providestogether with attachments of the comminution device a path on which theknife ring, detached from its fastening means, can be pulled axially outof the housing of the comminution device onto the carriage.

For demounting the knife ring, U.S. Pat. No. 5,313,696 suggests toarrange it, including its attachment components, its positioningcomponents, and its drive components, on a support whose path, extendingparallel to the axis of rotation, enables an axial movement of thecomplete comminution unit before the knife ring is removed by means of acrane and replaced by a newly furnished knife ring.

The disadvantage of these solutions is that for a knife exchange thecomplete knife ring must be exchanged. In addition to requiring anadditional knife ring, this results in a great technical expenditure,for example, for a tool change carriage and the elements connectedthereto for coupling the carriage or for a support for axially pushingout the complete comminution unit. The labor expenditure for mountingand demounting the knife ring must be added to the time required forexchanging the knives of the knife ring so that this solution is notsatisfactory with respect to economic efficiency.

How the actual change of the comminution tools, i.e., their mounting inand demounting from the knife ring is carried out, is not disclosed inthese prior art references.

Suggestions in this respect can be taken from German patent 41 14 840 C2describing a method and a device for exchanging the knives of a knifering wherein here the knife ring must first be demounted from thecomminution device and must be placed into a knife changing device. Inthis knife changing device an automatic knife exchange takes place bymeans of a magazine in which the knives arranged in the knife ring,after having been released from their fastening means, are first pushedout individually and sequentially from the knife ring and are thentransported on a carriage axially to the magazine where they are placedin the radial direction into the magazine.

In comparison to the prior art known at the time the invention accordingto 41 14 840 C2 was made, this method and this device provided asignificant technological advance. However, this type of knife exchangeis also possible only with the knife rings being removed from thecomminution device wherein the individual knives are successivelyexchanged. The simultaneous exchange of several knives is not possiblewith this method and this device.

From German patent 33 09 517 C1 a knife exchange is known which ispossible with the knife ring mounted in the comminution device. For thispurpose, magazines are arranged at the end face of the knife ring whichare in the form of a roll for steel strip knives or a cassette fordisposable (single-use) knives, wherein the knives are moved by means ofan axially acting advancing device into the knife ring. These solutionsare said to enable a knife exchange even during operation of astrand-producing chopping device.

A similar approach is also known from German published patentapplication 19 26 777. Here a magazine having dimensions matching thoseof the knife ring is placed axially onto the knife ring. Afterdetachment of the fastening means of the knives in the knife ring theyare pushed out simultaneously with the action of pushing in theresharpened knives on the other side of the knife ring.

The two last mentioned methods for exchanging the spent knives of theknife ring has the disadvantage that at the front side as well as at thebackside of the knife ring a high technical expenditure must be providedin order to push on one side the resharpened knives into the knife ringand to remove at the opposite side the spent knives from the knife ring.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a method and adevice which enable a completely automatic knife exchange which can beperformed with minimal technical expenditure within an extremely shortperiod of time.

In accordance with the present invention, this is achieved in regard tothe method in that the spent knife units, after detachment of theirfastening means in the knife ring, are pushed or pulled in the axialdirection out of the knife ring into an empty compartment within theknife changing magazine and, subsequently, a relative movement betweenthe knife changing magazine and the knife ring is carried out until aknife changing position has been reached in which the knife units whichhave been resharpened are aligned with the knife receptacles in theknife ring and the resharpened knife units are moved from the knifechanging magazine in the opposite direction into the knife ring.

In regard to the arrangement this is achieved according to the inventionin that a unit for releasing and fastening the knife units in the knifering is provided, in that a pushing unit is provided which is arrangedaxially opposite the end faces of the knife ring and which is suitableto transport at least one knife unit positioned in the knife exchangeposition axially out of the knife ring into the knife changing magazine,in that at least one unit for performing a relative movement between theknife changing magazine and the knife ring is provided, and in that aninsertion unit is provided which is suitable to axially push or pull atleast one knife unit out of the knife changing magazine into the knifering.

In regard to the device for comminuting, this object is achieved in thatthe pushing elements are arranged on a transverse beam onto which theadvancing drive acts.

In regard to the knife changing magazine, this is achieved in that theknife changing magazine has at least one more receiving area than knifegroups to be exchanged

The present invention is based on the principal idea that a completelyautomatic exchange of the knife units of a knife ring is to be enabledwithout requiring any human intervention. When carrying out the method,the detection, governing, and control of the individual operating statesof the method are realized by a programmable automatic sequence control.

When personnel is still to be used to some extent, the knife exchangecan also be performed semi-automatically. In the semi-automatic variant,the knife units are pushed out of the knife ring only partially and arethen removed by hand from the knife ring and replaced by resharpenedknives. This variant of the invention is suitable in connection with thedevice according to the invention having the pushing elements arrangedon a transverse beam onto which the advancing drive acts.

The automated knife exchange makes the operator of the comminutionmachines according to the invention independent of the possibleshortcomings of the employed personnel; often it is these shortcomingsof the personnel that cause damage to the slicing machines or lowerquality of the wood strands. Moreover, the knife exchange in the pastrequired great physical expenditure and presented a great risk ofinjuries as a result of the great weight and the unwieldy configurationof the knife units as well as the sharp cutting edges of the knives. Theautomation which can be achieved by means of the invention eliminates asource of injury for the good and the health of the operating personnel.

The reduction of the downtime of the comminution machines when employingthe inventive method is of economical and thus imminent importance forthe operator of comminution machines. Since the knives of comminutionmachines must be exchanged four times, or even more frequently, eachday, the time which is saved for each knife exchange by means of thepresent invention over the course of time results in a significantadvantage with regard to costs.

The exchange of the knife units according to the invention can berealized for the mounted as well as demounted knife ring; this providesgreat flexibility. The method according to the invention and the deviceaccording to the invention enable an exchange of groups of knife unitswherein the number of knife units in a group comprises in the extremesituation at least one knife unit and a maximum of all knife units of aknife ring. Preferred are however knife groups which contain one fourthup to one sixteenth of all knife units of a knife ring so that with acycle time between four and 16 a complete exchange of the knife unitscan be performed. In this way, an optimum of time savings and a minimumof constructive expenditure, enabling a compact design of thecomminution machines, are realized.

The method and the device according to the invention require only asingle knife changing magazine so that the constructive expenditure islimited to a minimum. This is enabled in that simultaneously the knifechanging magazine is used as a storage container for the knife unitswhich have been resharpened for the knife exchange and, on the otherhand, for receiving the worn or spent knives from the knife ring so thatthe manufacturing costs relative to other devices are significantlyreduced.

Since the knife exchange substantially is carried out only at theforward end face of a knife ring and substantially all components forperforming the knife exchange are arranged here, this configuration alsoenables an extremely compact and thus space-saving design. With respectto servicing and repairs, this has the advantage of improvedaccessibility of the device according to the invention.

For performing a relative movement between the knife ring and the knifechanging magazine after the worn knife units have been pushed out fromthe knife ring, a movement of the knife changing magazines is preferredaccording to the invention even though an adjustment of the knife ringwould be possible. This preference is based on the smaller mass of theknife changing magazine which therefore enables with a reduced forceexpenditure a quicker realization of the relative movement. Forrealizing the relative movement, axial movements or pivot movements ofthe knife changing magazines relative to the knife ring are basicallyalso possible. According to the invention, a horizontal or verticaldisplacement possibility is preferred because such a configurationrequires the smallest space and, in this way, the compact configurationof the device of according to the invention can be further improved. Avertically performed relative movement provides, primarily incombination with a two-level construction of the comminution machine,the advantage that the knife exchange magazine with spent knife unitsduring the course of relative movement can be advanced, for example, toa sharpening device arranged underneath the comminution machine.

When the exchange of the knife units is not carried out at once but in acycled fashion, after each exchange of a knife group a further relativemovement between knife changing magazine and knife ring must occur inorder to move a section of the knife ring to be furnished withresharpened knife units from the knife changing magazine into theexchange position so that the old knives of the knife ring can bereceived. In principle, this relative movement can also be performed bythe knife changing magazine. However, it is advantageous to define afictitious knife changing position into which the knife changingmagazine as well as the knife ring are moved. While for the knifechanging magazine, as described, a horizontal or vertical adjustmentmovement is suggested, the invention prefers in this connection arotational movement of the knife ring. In this way, a decoupling, andthus simplification, of the movement sequence is realized which also hasan effect in regard to a simplified configuration of the comminutiondevice.

A preferred embodiment of the invention provides that the knife unitsduring the steps of being pushed out and being inserted are guidedadditionally. This is known primarily in connection with devices inwhich the knife changing magazine is arranged at an axial spacing fromthe end face of the knife ring. By means of an additional guiding it isensured that the knife units reach precisely the receptacles of theknife ring or of the knife changing magazine. The guide arrangementtherefore contributes significantly to improving the operational safety.

The signal for the knife exchange can be realized as a function of timebut also as a function of the quality of the produced wood strands. Theinvention prefers however an energy-dependent control of the knifeexchange because, in this way, the special wear state of the knife unitsis taken into consideration.

The operation of a comminution device also entails that the finematerial will deposit within the knife receptacles of the knife ring.Since the boundary surfaces of the receptacles are also referencesurfaces for the resharpened knife units, which are adjusted relative tothe reference surfaces with regard to their geometry in order to finallyreach the nominal position, dirt deposits cause a falsification of thereference surfaces so that the resharpened knife units are mounted inthe knife ring in a position which deviates from the nominal position.In order to prevent this, it is suggested according to the invention toperform a cleaning of the receptacles, and thus of the referencesurfaces of the knife ring, between the steps of pushing the knife unitsout of the knife ring and inserting the resharpened knife units into theknife ring. The cleaning action can be realized mechanically by means ofa slide which frees the reference surfaces from dirt deposits, forexample, during insertion of and/or pushing out the knife units. A slideis suitable, in particular, for cleaning planar surfaces. Anotherpossibility according to the invention is provided by generating a fluidflow in the receptacles of the knife ring. For this purpose, a nozzlecan be arranged at the end of a receptacle where the end face is or canbe introduced together with the pushing unit into the receptacles. Inthis way, even locations which are difficult to access can be cleaned.

A further possibility of cleaning of the receptacle of a knife ringaccording to the invention is the use of a milling brush which is usedalone or in combination with the aforementioned measures.

In order to ensure that the knife units which have been resharpened areactually mounted in the nominal position within the knife ring afterknife exchange, according to a special embodiment of the invention it issuggested to monitor by means of a measuring device the nominal positionof the knife units within the knife ring. In this connection, the radialprojecting length of the cutting edges of the knife units past the innerwall of the knife ring is monitored as well as the axial insertion depthof the knife units into the knife ring. Only when the controlmeasurements indicate a proper position of the knife units, the exchangeof the knife units can be continued. In this way, damage of thecomminution machine is prevented which, for example, could result by atoo large radial projecting length of the cutting edge into thecomminution space. Particularly when carrying out a completely automatedknife exchange, the realization of control measures is of greatimportance because monitoring by an operator, who is capable ofrecognizing severe mounting errors of the knife units with ease, is nolonger possible. Ensuring mounting of the knife units in the nominalposition by means of an additional control measurement significantlyincreases at the same time the quality of the produced wood strands.

The invention will be explained in the following with embodimentsillustrated in the drawings in the form of a long-cut wood slicingdevice with rotating knife ring. It is understood that the invention isnot limited to such comminution devices; devices are also included whichhave comparable comminution tools which are arranged in a tool ring andaxially removed from or inserted into the tool ring. Screen millingelements or grinding track elements of mills are mentioned as an examplein this context.

BRIEF DESCRIPTION OF THE DRAWING

In the drawing:

FIG. 1 shows a schematic view of a knife ring slicing device;

FIG. 2 shows a cross-section along the section line II—II of the knifering slicing device with knife changing unit as illustrated in FIG. 1;

FIG. 3 shows a horizontal section along the section line III—III of theknife ring slicing device with knife changing unit as illustrated inFIG. 2;

FIG. 4 shows in partial cross-section a view of the knife ring slicingdevice illustrated in FIG. 3 in the area of the knife changing unitalong the section line IV—IV, wherein a first embodiment of the knifechanging unit is illustrated;

FIG. 5 shows in partial cross-section a view of the knife ring slicingdevice illustrated in FIG. 3 in the area of the knife changing unitalong the section line IV—IV, wherein a second embodiment of the knifechanging unit is illustrated;

FIG. 6 shows in partial cross-section a view of the knife ring slicingdevice illustrated in FIG. 3 in the area of the knife changing unitalong the section line IV—IV, wherein a third embodiment of the knifechanging unit is illustrated;

FIG. 7 shows in partial cross-section a view of the knife ring slicingdevice illustrated in FIG. 3 in the area of the knife changing unitalong the section line IV—IV, wherein a fourth embodiment of the knifechanging unit is illustrated;

FIG. 8 shows a partial cross-sectional view of a knife changing unitwith integrated cleaning device in detail;

FIG. 9 shows schematically a detail view of a first embodiment of thecoupling between the pushing element of the knife changing unit and theknife unit;

FIG. 10 shows schematically a detail view of a second embodiment of thecoupling between the pushing element of the knife changing unit and theknife unit;

FIG. 11 shows schematically a detail view of a third embodiment of thecoupling between the pushing element of the knife changing unit and theknife unit;

FIG. 12 shows schematically a detail view of a fourth embodiment of thecoupling between the pushing element of the knife changing unit and theknife unit;

FIG. 13 shows schematically a detail view of a fifth embodiment of thecoupling between the pushing element of the knife changing unit and theknife unit;

FIG. 14 shows schematically a detail view of a sixth embodiment of thecoupling between the pushing element of the knife changing unit and theknife unit;

FIGS. 15a and 15 b show schematically a detail view of a seventhembodiment of the coupling between the pushing element of the knifechanging unit and the knife unit in two different positions;

FIG. 16 shows a side view of the pushing element of the knife changingunit with integrated cleaning nozzles;

FIG. 17 shows a cross-section along the line XVII—XVII of the pushingelement illustrated in FIG. 16;

FIG. 18 shows a view of a movable knife changing magazine including itsdrive;

FIG. 19 shows a horizontal section along the line XIX—XIX of themagazine illustrated in FIG. 18;

FIG. 20 shows a partial view of the knife changing magazine illustratedin FIG. 18 in the area of the knife receptacles;

FIG. 21 is a view of a further embodiment of the knife changingmagazine;

FIG. 22 shows a further arrangement of a knife changing unit on a knifering slicing device in a plan view;

FIG. 23 shows a cross-section along the line XXIII—XXIII of FIG. 22;

FIG. 24 shows a further arrangement of a knife changing unit on a knifering slicing device in a plan view;

FIG. 25 shows a cross-section along the line XXV—XXV of FIG. 24;

FIG. 26 shows a knife ring slicing device with knife changing unit in afirst operating state during the knife exchange;

FIG. 27 shows the knife ring slicing device with knife changing unit ofFIG. 26 in a second operating state during the knife exchange;

FIG. 28 shows the knife ring slicing device with knife changing unit ofFIG. 26 in a third operating state during the knife exchange;

FIG. 29 shows the knife ring slicing device with knife changing unit ofFIG. 26 in a fourth operating state during the knife exchange;

FIG. 30 shows the knife ring slicing device with knife changing unit ofFIG. 26 in a fifth operating state during the knife exchange; and

FIG. 31 shows the knife ring slicing device with knife changing unit ofFIG. 27 in a sixth operating state during the knife exchange.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows in a schematic view a knife ring slicing device 1. Theknife ring slicing device 1 has a knife ring 3 arranged within a machinehousing 2 which is transversely movable on a base frame 4 of the machineacross the stationary substructure 5 of the machine in the direction ofthe double arrow. The drive of the knife ring 2 is realized by a drive 6also arranged on the basic frame 4 of the machine.

In FIG. 3 the configuration of the knife ring slicing device 1 is shownin more detail. Also shown is a knife changing unit 34, required for theknife exchange, in a simplified illustration. Illustrated is thetransversely movable base frame 4 on wheels 24 to which the machinehousing 2 is connected fixedly. The machine housing 2 has at its frontside 7 a central circular opening 8. The back wall 23 of the housing 2however is penetrated by a horizontally arranged drive shaft 9 which isfreely rotatably supported on a self-aligning roller bearing. The end ofthe drive shaft 9 outside of the housing 2 supports a disk 10 havingseveral grooves and connected by means of the drive belt 11 with anelectric motor 12. A braking and indexing disc 13 is mounted on themulti-groove disk 10 like an annular flange which is correlated with adisc brake 14 of the housing 2. In immediate vicinity to the braking andindexing disc 13 an initiator 136 is arranged which transmits togetherwith the braking and indexing disc 13 the respective position of themulti-groove disc and thus of the knife ring 3 to the programmedautomatic sequence control 39. A knife ring locking device 37 arrangedon the housing 2 is provided in order to secure a predetermined positionof the knife ring 3 relative to the housing 2, as, for example, theknife changing position.

On the end of the drive shaft 9 positioned in the housing 2 a supportdisc 15 is seated coaxial to the drive shaft 9. The knife ring 3 isdetachably fastened on the disc 15.

The knife ring 3 is comprised of a first annular disc 16 and a secondconcentric annular disc 17 which are connected to one another by knifecarriers 18 which are uniformly distributed about the circumference andaxially aligned and secured at a spacing to one another. The knifecarriers 18 have axial knife receptacles 40, respectively, into whichthe knife units 19 are inserted and fastened. The knife units 19 in thepresent case are comprised of a slicing knife and a knife holding plate;however, in principle, they can also be comprised simply of the slicingknife itself.

In FIGS. 1 and 4 through 7, the knife receptacles 40 and knife units 19are illustrated only in a simplify illustration wherein the knife units19 shown in dash-dotted line are already pushed out of the knifereceptacles 40.

The slicing chamber 20 is formed thus by the support disc 15 and thecircular space surrounded by the knife ring 3 into which the material tobe comminuted is introduced in the axial direction via the opening 8. Byrotating the knife ring 3 about the axis of rotation 21 and a relativemovement between the knife ring 3 and the material to be comminuted bytransverse movement of the base frame 4 of the machine, the slicingoperation is carried out wherein the comminuted material exits in theradial direction through the knife ring 3 and exits the knife ringslicing device 1 within the housing 2 through an opening 22 at thebottom side and is then transported away, for example, by a conveyorbelt.

On the front side 7 of the knife ring slicing device 1 at the level ofthe axis of rotation 21 and axially opposite a portion of the annulardisc 17, a knife changing magazine 25 is arranged which is movable on astationary substructure 26 along the front side 7 the knife ring slicingdevice 1. The stationary substructure 26 for this purpose is provided atits upper side with two rails 27, a drive 28, as well as a travelmeasuring system 29, comprised of an index bolt 40 and initiators 31.The rails 27 form a path for the wheels 32 of a carriage 33 which isconnected fixedly with the movable part of the drive 28. The top side ofthe carriage 33 serves for receiving the knife changing magazine 25.

The knife changing magazine 25 has a plurality of axial knifereceptacles 45 which can be moved by means of the drive 28 into aposition axially aligned with the knife receptacles 40 of the knifecarriers 18. Further details of the knife changing magazine 25 aredescribed in connection with FIGS. 19 and 20.

In the area of the back wall 23 of the housing 2, a section of theannular disc 16 is arranged axially opposed thereto and a knife changingunit 34 is arranged approximately at the level of the axis of rotation21 and fixedly attached to the base frame 4 of the machine. The knifechanging unit 34 houses several pushing elements 35 of which only one,representative of all the others, is illustrated in FIG. 2. The pushingelements 35 are supported axially movably in the knife changing unit 34,and, as illustrated by arrow 36, can be pushed in the axial directionout of the knife changing unit 34 and can be introduced through openingsin the back wall 23, the support disc 15, and the annular disc 16 intothe knife receptacles 40 of the knife carriers 18. In this way, theknife unit 19 positioned within the knife receptacles 40 is pushed outof the knife ring 3 and is moved into a knife receptacle 45 (FIG. 20)within the knife changing magazine 25.

Different embodiments of the knife changing unit 34 described inconnection with FIGS. 1 through 3 are illustrated in FIGS. 4 through 7.The knife ring slicing device 1 corresponds to the knife ring slicingdevice 1 illustrated in FIGS. 1 through 3 so that the reference numeralsused therein are also employed in FIGS. 4 to 7. In contrast to the knifering slicing device illustrated in FIGS. 1 through 3, the embodimentillustrated in FIGS. 4 through 7 of the invention has no knife changingmagazine at the front side 7 of the knife ring slicing device 1 and issuitable therefore particularly for performing a semi-automatic methodfor changing the knife units 19 in which individual knife units 19 orgroups of knife units 19 are pushed only partially out of the knifereceptacles 40 of the knife ring 3 and are then completely removed byhand and replaced by knife units 19′ which have been resharpened.

By combining or supplementing such a semi-automatic embodiment of theinvention with a knife changing magazine 25 and an insertion unit, acompletely automated arrangement for changing the knife units 19 of theknife ring 3 results.

The knife changing unit 34 illustrated in FIG. 4 is comprised of a framewhich is formed by an inner rectangular plate 48 and an opposedrectangular plate 49 positioned at a spacing thereto. Both plates 48 and49 are connected fixedly with the base frame 4 of the machine; the plate48 is additionally connected with the back wall 23 of the machinehousing 2. The two plates 48 and 49 are connected with one another byguide elements arranged on each corner, respectively. Moreover, theplates 48 and 49 provide a central rotary bearing for a spindle 51extending between the plates 48 and 49. The spindle 51 is driven at itsend by a drive 52.

Slidable guide bushings 53 are provided on the guide elements 50 and areconnected to one another by a transverse beam 54 arranged parallel tothe plates 48 and 49. At the center of the transverse beam 54 a spindlenut 55 is fastened which is seated on the spindle 51. Moreover, pushingelements 35 are arranged axis-parallel to the spindle 51 on thetransverse beam 54 and are moveably supported with their free ends inbores in the plate 48.

By rotation of the spindle 51, the spindle nut 55 and together with itthe transverse beam 54 are moved toward or away from the knife ring 3,depending on the rotational direction, as illustrated by the doublearrow. In this way, the pushing elements 35 can be introduced viacorresponding bores in the back wall 23 of the housing 2 and in thesupport disc 15 as well as the annular disc 16 into the knifereceptacles 40 within the knife ring 3. Here they impact on the knifeunits 19 and move them in the axial direction at the front side of theknife ring 3 out of the knife receptacle 40. This state of the knifeunits 19 is illustrated in dashed lines in FIGS. 4 through 6.

A slight variation of the embodiment illustrated in FIG. 4 is shown inFIG. 6 so that for same parts the same reference numerals are used.

Instead of a central spindle, two parallel spindles 56 and 57 are usedwhich are arranged between the pushing elements 35 and which are drivenin the way described above for movement of the transverse beam 54 bymeans of a synchronizing drive. In this way, the transverse beam 54glides along the outer guide elements 50.

A further embodiment of the knife changing unit 34, as illustrated inFIG. 5, has two outwardly positioned spindles 58 and 59, which form, inaddition to the centrally arranged guide element 60, also a guide forthe transverse beam 54. Pushing out or inserting the pushing elements 35is also realized by synchronously driving the spindles 58 and 59.

The knife changing unit 34 illustrated in FIG. 7 provides asimplification of the knife changing unit 34 illustrated in FIG. 4. Inthis embodiment, the externally positioned guide elements for thetransverse beam 54 are eliminated. Instead, a spindle 61 arrangedaxis-parallel to the axis of rotation 21 is fastened on two bearingplates 62 and 63. The lower pushing elements 35 are moveably supportedin two bores of the bearing plate 63 positioned opposite the housing 2,and, in this way, rotation of the transverse beam 54 and of the pushingelements 35 is prevented. In this embodiment of the invention, thespindle 61 provides the advancing function as well as the guidingfunction.

FIG. 8 shows a partial cross-section of the area in which the pushingelements 35 penetrate the knife ring slicing device 1. A section of theback wall 23 of the housing 2 is shown as well as a section of thesupport disc 15 arranged at a spacing thereto and fixedly connected withthe annular disc 16. At the inner side of the annular disc 16, the endof a blade unit 19 at the end face is illustrated which is introducedinto a knife receptacle 40 of a blade carrier 18 (not illustrated indetail) and rests with its end face against the lateral surface of theannular disc 16. The support disc 15 and the annular disc 16 as well asthe back wall 23 of the housing 2 have an aligned bore 64, 64′ whichextend directly to the end face of the knife unit 19.

Extending from the left edge of the sheet, the forward end of a pushingelement 35 is illustrated which has already penetrated the back wall 23of the housing 2 and whose tip is in a position immediately beforepenetration of the bore 64 of the support disc 15. Upon furtherinsertion of the pushing element 35, its tip reaches the end face of theknife unit 19 and forces it out of the knife receptacle 40 since thepushing element 35 continues to be driven.

In addition, a cleaning device for cleaning the knife receptacle 40 inthe knife carrier 18 during the process of pushing out the knife unit 19is illustrated in FIG. 8. A sealing element 65 is screwed onto the leftside, in the plane of the illustration, of the back wall 23 and providesa seal-tight enclosure of the pushing element 35 even during theadvancing movement. On the opposite side of the back wall 23 of thehousing 2 a nozzle 66 is arranged whose hollow-cylindrical end 67projects to the bore 64 in the support disc 15. The nozzle base 68 iswidened for forming a chamber and has a penetration 69 for loading thenozzle 66 with a fluid flow. The cleaning nozzle 66 surrounds with itshollow-cylindrical portion 67 the pushing element 35 with a minimalannular gap 70 being provided between the portion 67 and the pushingelement 35. When loading the nozzle 66 with a fluid under pressure, afluid flow results in the annular gap 70 and extends further along themantle surface of the pushing element 35. In this way, a cleaning actionof the knife receptacles 40 during knife exchange takes place with theinsertion of the pushing element 35 into the knife receptacles 40.

According to one embodiment of the invention, the knife changing unit 34is of a unitary configuration, i.e., the knife units 19 are moved out ofthe knife receptacles 40 of the knife ring 3 from one side of the knifering, and the insertion of the resharpened knife units 19′ from theknife changing magazine 25 into the receptacles 40 of the knife ring 3is carried out also from the same side (FIGS. 2 and 3 and FIGS. 22 and23).

In these situations, it is required to provide a pulling-resistantconnection between the pushing elements 35 and the knife unitspositioned in the knife receptacles of the knife changing magazine 25.Different solutions are illustrated in FIGS. 9 through 15 with which apulling-resistant and pushing-stable connection between the pushingelement 35 and the blade unit 19, 19′ can be provided.

In FIGS. 9 through 15 the leading end of a pushing element 35 isillustrated onto which a coupling head 71 is positioned, respectively.FIG. 9 shows the coupling head 71 comprised of a truncated cone portionwhich is introduced into a matching truncated cone-shaped receptacle inthe end face of the knife unit 19, 19′. As a result of the slant of thelateral surfaces of less than 2° relative to the mantle surface of thepushing element 35, a frictional connection results which is loadablewith regard to pressure as well as tension. Releasing this connection isrealized by contacting a surface 72. This causes the clamping forceproduced by the frictional connection to be overcome so that thetruncated cone and thus the pushing element 35 come free.

In an alternative connecting possibility (FIG. 10), the coupling head 71has one or several radial bores 73 into which a pressure spring 47 isintroduced and on which, in turn, a ball 75 is seated as a lockingelement. The opening of the bore 73 is slightly narrowed so that theball 75 is captive in the bore.

In the end face of the knife element 19, 19′ a cylindrical recess isprovided which has at its inner side an annular groove 76. Uponinsertion of the pushing element 35 into the recess of the knife element19, 19′, first the ball 75 is radially pushed against the spring forceand subsequently snaps into place in the annular groove 76 of the knifeunit 19, 19′ upon further insertion of the pushing element 35.

The coupling head 71 of FIGS. 11 and 12 is provided with a solenoid orpermanent magnet 78. The magnet or solenoid can be connected directlywith the smooth end face of a knife unit 19, 19′ (FIG. 11) or can beintroduced into a recess, matching the solenoid or magnet shape, in theend face of the knife unit 19, 19′ (FIG. 12).

The solution illustrated in FIG. 13 shows the knife unit 19, 19′ havinga cylindrical recess 79 on whose inner side the spring elements 80,already described in connection with FIG. 10, are arranged in a commonradial plane. These spring elements 80 snap into place with theirball-shaped latch in an annular groove 93 in the coupling head 71 of thepushing element 35.

In the connection illustrated in FIG. 14 between the pushing element andthe knife unit 19, 19′ a nonpositive connection by means of positive fitis obtained. For this purpose, the coupling head 71 has a groove 82 intowhich a projection 83 of the knife unit 19, 19′ engages. For producingthe positive fit connection, the coupling head 71 is introducedperpendicularly to the plane of illustration into the recess in theknife unit 19, 19′ or is rotated about its longitudinal axis.

A further possibility of providing a pull-resistant connection betweenthe pushing element 35 and the knife unit 19, 19′ is described inconnection with FIGS. 15a and 15 b. The knife unit 19, 19′ illustratedtherein has at its end face a cylindrical recess in whose mantle surfacean annular groove 84 is provided. The coupling head 71 has a ball 86which is moveably arranged within a radial guide and serves as a latch;it cooperates with the annular groove 84 of the knife unit 19, 19′. Foractuating the ball 86, an axially movable control element 87 is providedwithin the coupling head 71. It can be separately controlled and has twoglide surfaces 81 and 85 for the ball 86 which are positioned atdifferent levels relative to one another and connected by a ramp. Apressure spring 88 acts between the end of the coupling head 71 and theend of the control element 87 at the end face.

By coaxial movement of the control element 87 counter to the springforce of the coil spring 88, the ball 86 is pushed radially outwardly bythe glide surface 81 via the ramp and the glide surface 85 and snapsinto place in the annular groove 84 of the knife unit 19, 19′. A releaseof the locking action is realized in the reverse order so that by axialmovement of the control element 87 in the direction of the spring forcea lowering of the ball 86 onto the lower glide surface 81 of the controlelement 87 is possible and the annular groove 84 is released in thisway.

FIGS. 16 and 17 show an alternative or additionally embodiment of thecleaning device relative to FIG. 8 for the knife receptacles 40 in theknife ring 3. The pushing element 35 is illustrated which is in the formof a hollow cylinder and which is moved into a nonpositive connectionwith a knife unit 19 by means of the coupling head 71 described inconnection with FIGS. 9 through 15. In the vicinity of the coupling head71 radially acting cleaning nozzles 90 are arranged. They are connectedvia the hollow cylinder of the pushing element 35 to the cleaning systemwhich ensures the exit of a cleaning fluid and/or a gas, for example,air, out of the nozzles 90 at high pressure.

FIG. 17 shows also a part of the knife carrier 18 in the area of theknife receptacle 40. In the dashed illustration a part of the knife unit19 is shown in a position in which it is arranged in the knifereceptacle 40 during the pushing out movement. Moreover, FIG. 18 showsthe bore in the annular disc 26, which bore is identified by referencenumeral 64 in FIG. 8. The pushing element 35 reaches the knifereceptacles 40 in the knife carrier 18 via the bore 64.

FIGS. 18 and 19 show details of the configuration of the knife changingmagazine 25 including the adjusting device 95 for horizontal adjustmentof the knife changing magazine 25 into the knife changing position.

The knife changing magazine 25 is comprised substantially of the lateralparts 96 and 97 which are arranged parallel and at a spacing to oneanother. The lateral parts 96 and 97 are connected rigidly by means ofbolts 98 provided at the corners. The lateral parts 96 and 97 have aplurality of slot-shaped recesses 99. The recesses 99 are arranged aboveone another and form groups wherein the individual groups are arrangedon parallel circular arc sections. The number of recesses 99 of acircular arc section corresponds to the number of pushing elements 35 ofthe knife changing unit 34 and thus to the number of knife units 19which can be changed simultaneously by a single exchange operation. Theslants of the recesses 99 of a circular arc section changes from recess99 to recess 99 and correspond exactly to the slant of the knife units19 mounted in the knife ring 3. The recesses 99 in the lateral part 96are arranged congruently with the recesses 99 in the lateral part 97.

Between two oppositely positioned recesses 99 of the lateral parts 96and 97, angle elements 100 and 101 (FIG. 20) connecting the recesses 99,respectively, are inserted whose legs form gliding and stop surfaces forthe knife unit 19, 19′. In this way, the angle elements 100 and 101 aswell as the lateral parts 96 and 97 including the recesses 99 provide aplurality of knife receptacles 45 in the knife changing magazine 35 intowhich the knife units 19, 19′ can pushed or from which they can beremoved.

For the knife exchange method according to the invention, the totalnumber of knife receptacles 45 is based on the number of knife units 19to be exchanged plus the number of knife receptacles 45 required for thenumber of knife units 19 of a group to be simultaneously exchanged.Because of this, in FIGS. 18 and 19 additional knife receptacles 45 of acircular section are without resharpened knife units 19′ while the otherknife receptacles 45 are provided with resharpened knife units 19′.

Such a knife changing magazine 25 is moved by means of the adjustingdevice 95 into the suitable knife changing position. The adjustingdevice 95 has a carriage 33 which can be linearly moved on a stationarysubstructure 26 as indicated by the arrow 102. A centering bolt 119projects from the plane top side of the carriage 33 and matches a recessin the underside of the knife changing magazine 25. The carriage 33 isdriven by a drive 28 which is, for example, a spindle drive, a toothedrack drive, a chain drive or the like.

The adjusting device 95 also includes a travel measuring system 29 whichis comprised of a strip stationarily arranged relative to thesubstructure 26 and provided with initiators 31. The initiators 31cooperate with index bolts 30 provided on the carriage 33.

For the knife exchange operation a knife changing magazine 25 furnishedwith resharpened knife units 19′ is placed by means of a crane 103 ontothe carriage 33, wherein a centering of the knife changing magazine 25relative to the carriage 33 is realized by means of the centering bolt119.

The stationary substructure 26 and the travel measuring system 29 form astationary unit relative to the knife ring slicing device 1 so that, bymeans of the height of the substructure 26 and the position of thecarriage 33, determined by the travel measuring system 29, a precisepositioning of the knife changing magazine 25 relative to the knife ringslicing device 1 can be realized.

FIG. 21 shows an alternative embodiment of a knife changing magazine 25.It is comprised of two opposed coaxially positioned, spaced apart ringsof which in FIG. 21 only one is illustrated and identified withreference numeral 104. The two rings have recesses wherein oppositelyarranged recesses are connected with one another in the axial directionby means of gliding and guiding elements so that in this way axial knifereceptacles are formed in the knife changing magazine 25. Thearrangement of the knife receptacles corresponds exactly to thearrangement of the knife units 19 in the knife ring 3 of the knife ringslicing device 1. Also shown are contact surfaces 105 uniformlydistributed about the outer circumference.

The carriage 33 has at its top side two axial, freely rotatable rollers106 and 107 which are provided for supporting and simultaneouslycentering the knife changing magazine 25. Moreover, a cylinder/pistonunit 108 is connected to the top side of the carriage 33 whose movablepiston upon being extended impacts on a contact surface 105 and in thisway causes the knife changing magazine 25 to be rotated in order tobring a neighboring ring section into the knife changing position.

FIG. 22 and FIG. 23 show an alternative embodiment of the invention. Theillustrated knife ring slicing device 1 corresponds to that illustratedin FIGS. 1 through 3 so that identical reference numerals are used andreference is being had to the corresponding description. Differencesreside only in the arrangement of the knife changing unit 34 which inFIGS. 22 and 23 is arranged at the front side 7 with intermediatepositioning of the knife changing magazine 25 instead of opposite theback wall 23 of the knife ring slicing device 1. The knife changing unit34 illustrated in FIGS. 22 and 23 has also pushing elements 35 which canbe brought into a pull-resistant and push-resistant connection with theknife units 19, 19′ so that the knife units 19, 19′ can be pushed aswell as pulled by the knife changing unit 34 which is illustrated byarrow 109. The knife exchange is carried out in this embodiment onlyfrom one side of the knife ring 3.

Since in this variant the pushing elements 35 of the knife changing unit34 no longer are introduced into the knife receptacles 40 in the knifering 3, cleaning of the knife receptacles 40 by means of the pushingelements 35 is no longer possible. For this reason, special cleaningelements 110 are arranged at the back wall 23 of the knife ring slicingdevice 1 which can be guided in the axial direction through the backwall 23 into the interior of the machine housing 2. The cleaningelements 110 are provided with several cleaning nozzles with which acleaning liquid and/or a gas, for example, air, can be supplied at highpressure into the knife receptacles from the inner side as well as theouter side of the knife carriers onto the knife ring 3.

FIGS. 24 and 25 show further embodiments of the invention wherein, as aresult of the identical configuration of the knife ring slicing device1, the same reference numerals as in FIGS. 1 through 3 are employed andreference is being had to the corresponding part of the description.

The knife changing unit illustrated in FIGS. 24 and 25 is divided intotwo spatially separate units. On the back wall 23 of the knife ringslicing device 1 the pushing unit 111 is arranged which carries out onlythe pushing movement for moving the knife units 19 out of the knife ring3 into the knife changing magazine 25. On the opposite side behind theknife changing magazine 25 the insertion unit 112 is arranged whichrealizes the pushing movement for moving the resharpened knife units 19′out of the knife changing magazine 25 into the empty knife receptacles40 in the knife ring 3. The arrows 113 and 114 show in which directionthe pushing unit 111 or the insertion unit 112 acts.

In this variant it is possible to integrate cleaning nozzles 90 into thepushing elements 35 of the pushing unit 111 so that the pushing-outmovement for moving the knife units 19 out of the knife ring 3 canrealize at the same time a cleaning of the knife receptacles 40.

FIGS. 26 through 31 show different operating states of the inventionwhen performing a knife exchange. By means of FIGS. 26 to 31 the methodaccording to the invention will be explained in the following in moredetail by means of a two-part knife exchange unit comprised of a pushingunit 111 and an insertion unit 112. The individual method steps aretriggered by a programmable automatic sequence control which receivesall of the data provided by the sensors and processes them andcalculates based thereon control commands which are then sent to theknife ring slicing unit 1 and the components necessary for the knifeexchange.

FIGS. 26 and 27 show the initial position of a knife ring slicing device1 with the pushing unit 111, the insertion unit 112, as well as theknife changing magazine 25 in the position A. In the initial positionfor the knife exchange the knife ring 3 has been moved into a knifechanging position. This is realized by a slow rotation of the knife ring3 by the drive 6 until the braking and indexing disc 13 in connectionwith the initiator 36 and the disc brake 14 stops the knife ring 3 in aposition in which the knife receptacles 40 in the knife ring 3 areaxially aligned with the pushing elements 35 of the pushing unit 111(see also FIG. 3). The knife pushing unit 111 is comprised in thepresent embodiment of several cylinder/piston units arranged in acircular arc pattern and fastened on the back wall 23 of the knife ringslicing device 1. Their movable pistons form the pushing elements 35. Inthe initial position the pushing elements 35 are retracted into thecylinders.

The knife changing magazine 25 corresponds to that described in FIGS. 18to 20. The knife changing magazine 25 is furnished with the same numberof resharpened knife units 19′ as are present within the knife ring 3.The resharpened knife units 19′ are grouped in the knife changingmagazine 25 in adjacently positioned circular arc sections. In addition,the knife changing magazine 25 has empty knife receptacles 45 whichcorrespond to the number of knife units 19 of a circular arc section.

The knife changing magazine 25 is deposited onto the carriage 33 and bymeans of the drive 28 and the travel measuring system 29 is moved intothe knife changing position where the empty knife receptacles 45 of theknife changing magazine 25 are axially aligned with the knifereceptacles 40 in the knife ring 3 and the pushing elements 35 of thepushing unit 111.

The insertion unit 112 arranged behind the knife changing magazine 25has, in principle, the same configuration as the pushing unit 111. Theinsertion unit 112 is fastened on a column 115 fixedly connected to thesubstructure 5 of the machine wherein the insertion elements 116 areretracted into the cylinders.

FIG. 28 shows the next method step in which the programmable automaticsequence control telescopes the pushing elements 35 out of the pushingunit 111 wherein they are moved through the openings in the back wall 23of the knife ring slicing device 1 and openings in the support disc 15and the annular disc 16 into the knife receptacles 40 in the knife ring3. Here, the pushing elements 35 impact on the end face of the knifeunits 19 previously detached from the fastening means of the knifecarriers 18 and push them in the axial direction out of the knife ring 3in the direction of the free receptacles 45 in the knife changingmagazine 25. In order to bridge the spacing between the knife ring 3 andthe knife changing magazine 25, at the front side 7 of the housing 2guide elements 117 (FIG. 27) are arranged which align the knife units 19precisely with the free knife receptacles 45 of the knife changingmagazine 25. The worn knife units 19 are pushed by the pushing elements35 to such an extent until they are received completely by the knifechanging magazine 25. Subsequently, the pushing elements 35 areretracted into their initial position.

Already during the pushing movement of the pushing elements 35 andoptionally also during the return movement the knife receptacles 40 inthe knife ring 3 are cleaned by cleaning nozzles 66 (FIG. 8) andoptionally by further cleaning nozzles in the head area of the pushingelements (FIGS. 16 and 17) with a water/air mixture at high pressure.

In the next step, as illustrated in FIG. 29 by the arrow 119, the knifechanging magazine 25 is moved to the side by one cycle. Now the firstcircular arc section with the resharpened knife units 19′ is in theknife changing position and aligned with the empty and cleaned knifereceptacles 40 in the knife ring 3. The amount by which the knifechanging magazine 25 must be laterally moved is determined by the travelmeasuring system 29 and this information is supplied to the programmableautomatic sequence control which controls the advancement of thecarriage 33 accordingly.

FIG. 30 shows the next method step in which the insertion elements 116of the insertion unit 112 are advanced in the direction of arrow 119wherein they impact on the end face of the resharpened knife units 19′,positioned in the knife changing magazine 25, and move the knife units19′ via the guide elements 117 into the free and cleaned knifereceptacles 40 in the knife ring 3 until the knife units 19′ contactwith the oppositely positioned end face the annular disc 16.Subsequently, the insertion elements 116 are retracted into their restposition. At the same time, the nominal position of the knife units 19′being inserted momentarily is monitored by means of non-representedsensors being part of a control unit. For example, the sensors can bephoto diodes or ultrasound distance measuring devices or infrareddistance measuring devices. Only when the control device affirms thenominal position of the blade units 19′, the knife units 19′ arefastened by generally known fastening devices in the knife ring 3.

The next and last method step of a knife changing cycle is illustratedin FIG. 31 where the arrow 12 shows the rotation of the knife ring 3about the axis of rotation 21. In this connection, the circular arcsection of the knife ring 3 which has just been provided with theresharpened knife units 19′ is moved out of the knife changing positionwherein at the same time a neighboring circular arc section of the knifering 3, which contains worn knife units 19, is moved into the knifechanging position. The amount of rotation of the knife ring 3 is againdetermined by the braking and indexing disc 13 and by means of theinitiators 136. In this position, the first cycle for exchanging a groupof knife units is completed, and a new cycle for exchanging the nextgroup of knife units is carried out according to the already describedone in connection with FIG. 27ff.

These process steps are continued until all worn knife units 19 of theknife ring 3 have been replaced with the resharpened knife units 19′ ofthe knife changing magazine 25. This situation is illustrated in FIG. 26by the position B of the knife changing magazine 25. From this positionthe knife changing magazine 25 containing the spent or worn knife units19 is removed by means of a crane to a resharpening station.

While specific embodiments of the invention have been shown anddescribed in detail to illustrate the inventive principles, it will beunderstood that the invention may be embodied otherwise withoutdeparting from such principles.

What is claimed is:
 1. An arrangement for automatically changing knifeunits of a knife ring slicing device: comprising: a knife changingmagazine moveable into a knife changing position in which at least twoknife receptacles of the knife changing magazine are axially alignedwith at least two knife receptacles of the knife ring, the knife ringhaving an axis of rotation and the knife receptacles being parallel tothe axis of rotation; a unit for releasing and fastening the knife unitsin the knife ring; a pushing unit arranged axially relative to end facesof the knife ring and configured to simultaneously convey at least twoof the knife units of the knife ring, in the knife changing position ofthe knife changing magazine, axially out of the knife ring in a push-outdirection into the knife changing magazine; a moving unit configured toperform a relative movement between the knife changing magazine and theknife ring; and an insertion unit arranged axially opposed to one of theend faces of the knife ring and configured to simulatneously move atleast two knife units that are in the knife changing position axiallyout of the knife changing magazine opposite the push-out directionaxially into the knife ring.
 2. The arrangement according to claim 1,wherein the moving unit has at least one unit from the group consistingof a first unit for performing a linear movement of the knife changingmagazine and a second unit for performing a rotational movement of theknife ring.
 3. The arrangement according to claim 2, wherein the firstunit has at least one drive from the group consisting of a horizontaldrive and a vertical drive.
 4. The arrangement according to claim 3,wherein the horizontal drive is selected from the group consisting of achain drive, a toothed rack drive, a spindle drive and a cylinder andpiston unit.
 5. The arrangement according to claim 3, wherein thevertical drive is selected from the group consisting of a chain drive, atoothed rack drive, a spindle drive and a cylinder and piston unit. 6.The arrangement according to claim 4, wherein the knife changingmagazine is configured to be horizontally moveable; or verticallymoveable; or horizontally and vertically moveable; or rotatable.
 7. Thearrangement according to claim 2, wherein the knife changing magazine isdivided into areas comprising the knife receptacles for the knife unitsdefining knife groups wherein the knife units of the knife groups are tobe exchanged at once, respectively.
 8. The arrangement according toclaim 7, wherein the number of areas of the knife changing magazine isgreater by at least one than a number of the knife groups to beexchanged.
 9. The arrangement according to claim 7, wherein the areas ofthe knife changing magazine are arranged horizontally adjacent to oneanother; or vertically above one another; or horizontally adjacent andvertically above one another; or along a circular arc.
 10. Thearrangement according to claim 7, wherein the pushing unit has a driveand pushing elements arranged in an aligned position with the knifechanging position, wherein the pushing elements are axially moveable bythe drive for being pushed into the knife receptacles of the knife ringand retracted from the knife receptacles of the knife ring, the pushingelements are present in a number corresponding to a number of the knifeunits forming the knife groups, respectively, wherein the pushing unitcomprises a transverse beam and a drive acting on the transverse beam,wherein the pushing elements are connected to the transverse beam andthe pushing elements are driven indirectly by the drive via thetransverse beam.
 11. The arrangement according to claim 1, wherein thepushing unit has a drive and pushing elements arranged in an alignedposition with the knife changing position, wherein the pushing elementsare axially moveable by the drive for being pushed into the knifereceptacles of the knife ring and retracted from the knife receptaclesof the knife ring.
 12. The arrangement according to claim 11, whereinthe drive is comprised of at least one cylinder and piston unit or atleast one spindle drive.
 13. The arrangement according to claim 11wherein the transverse beam has guide elements in which the transversebeam is movably supported.
 14. The arrangement according to claim 11,further comprising cleaning nozzles arranged on the pushing elements andconfigured to be loaded by fluid flow.
 15. The arrangement according toclaim 1, wherein the insertion unit comprising insertion elements isarranged at a knife changing side of the knife ring, wherein the knifechanging magazine is located between the knife ring and the insertionunit, wherein the insertion elements are in an aligned position with theknife changing position and are axially movable, wherein the insertionunit comprises a drive acting on the insertion elements so as to movethe insertion elements into and out of the knife receptacles of theknife changing magazine so that the resharpened knife units are movedout of the knife receptacles of the knife changing magazine into theknife receptacles of the knife ring.
 16. The arrangement according toclaim 15, wherein the drive is at least one cylinder/piston unit or atleast one spindle drive.
 17. The arrangement according to claim 15,wherein the insertion elements are present in a number corresponding toa number of the knife units forming knife groups, respectively, whereinthe insertion unit comprises a transverse beam and the drive acts on thetransverse beam, wherein the insertion elements are connected to thetransverse beam and the insertion elements are driven indirectly by thedrive via the transverse beam.
 18. The arrangement according to claim17, wherein the transverse beam is moveably arranged in guidingelements.
 19. The arrangement according to claim 1, wherein theinsertion unit is formed by the pushing unit comprising pushingelements, wherein the pushing elements for moving the knife units fromthe knife changing magazine into the knife receptacles of the knife ringare configured to be coupled by a coupling with the end faces of theknife units.
 20. The arrangement according to claim 19, wherein thecoupling is comprised of frictional connection surfaces.
 21. Thearrangement according to claim 19, wherein the coupling is comprised ofa magnet.
 22. The arrangement according to claim 19, wherein thecoupling is comprised of a latch cooperating with a latch receptacle.23. Arrangement according to claim 19, wherein between the knifechanging magazine and the knife ring at least one guide element isarranged and has a guide surface aligned with the knife receptacles ofthe knife changing magazine and the knife receptacles of the knife ringin the knife changing position.
 24. The arrangement according to claim23, wherein the ends of the guide elements have a widened portion,respectively.
 25. The arrangement according to claim 1, furthercomprising a measuring device for controlling at least one of a radialcutting-edge projection into a comminution chamber of the knife ringslicing device and an axial insertion depth of the knife units in theknife ring.
 26. The arrangement according to claim 25, wherein thearrangement is arranged on a knife ring slicing device.
 27. Thearrangement according to claim 1, wherein the arrangement is arranged ona resharpening device.